This invention relates generally to optical components including those used in optical communication networks.
In optical communication networks, a waveguide core may extend across a semiconductor substrate. The core may be covered by an upper cladding and may be positioned over a lower cladding. The core may define an optical signal path. The cladding may have a lower refractive index than the core.
In some cases the optical characteristics of the core may be thermally modified. For example, thermo-optic devices may be operated through the application of heat. The refractive index of an optical device may be changed by heating. Thermo-optic switches may be used in Mach-Zehnder interferometers and directional couplers, as two examples.
Generally, the more heat that is dissipated by the thermo-optic device, the more the power requirements of the overall component. It is desirable to reduce the heat transfer to only that needed to achieve the thermo-optic effect.
Thus, there is a need for ways to reduce the amount of heat loss in thermo-optic devices.